JP2887726B2 - Energy regenerative braking system for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy regenerative braking device for a vehicle, which recovers kinetic energy during deceleration of the vehicle and uses the kinetic energy as driving energy. The present invention relates to a technique for reducing gear rattling noise caused by a loss of gear load.

[0002]

2. Description of the Related Art Conventionally, as this kind of energy regenerative braking device, for example, devices disclosed in Japanese Patent Application Laid-Open Nos. 2-117435 and 4-212845 are known. In these devices, a diagonal shaft type pump motor is gear-connected to a wheel drive system via a gear clutch, and one port of the pump motor is connected to an accumulator on a high pressure side, and the other port is connected to a tank on a low pressure side. Connected to When the vehicle decelerates, the pump motor is connected to the wheel drive system to control the tilt angle of the oblique shaft to operate as a pump, thereby braking the wheel drive system with the pump motor as a load and applying high-pressure oil to the accumulator. To recover the kinetic energy of the vehicle. The high-pressure oil accumulated in the accumulator in this way is
For example, a pump motor is connected to a wheel drive system at the time of starting or the like and serves as an energy source to act as a motor, and is used as drive energy of the wheel drive system.

Further, in the former conventional device, the proportional control valve is electronically controlled so that the amount of depression of the brake pedal and the brake torque generated on the wheels correspond to the pressure accumulation state of the regenerative device. Further, in the latter conventional device, the regenerative brake is activated in a service brake (foot brake) non-operation region in which the amount of depression of a brake pedal is equal to or less than a predetermined value. Is supplied to the brake piping system in accordance with the amount of depression of the brake pedal to operate the service brake.

[0004]

In these conventional devices, the regenerative braking is released when the vehicle speed has decreased to some extent, and at this time, the tilt angle of the oblique shaft of the pump motor is immediately returned to the neutral position. Would. For this reason,
There is a problem that the load on the pump motor side acting on the gear in the gear box which is interposed between the wheel drive system and the pump motor and connects the both is eliminated, and the gear rattle occurs.

[0005] The present invention has been made in view of the above-mentioned circumstances, and at the time of switching from regenerative braking to service braking, a slight load is generated on the pump motor side until the vehicle speed becomes zero, so that the gear An object of the present invention is to provide an energy regenerative braking device for a vehicle that reduces rattle noise.

[0006]

Therefore, in the present invention,
When the regenerative brake operation condition is satisfied during the operation of the brake pedal, the tilt angle of the oblique axis of the pump motor is controlled in accordance with the amount of depression of the brake pedal, and the pump motor is connected to the wheel drive system via a gear. A regenerative braking device for a vehicle including a regenerative device for driving and accumulating high-pressure oil in an accumulator to collect brake energy and obtain a regenerative braking force according to the amount of depression of the brake pedal. A main brake circuit for outputting a pressure from a brake pressure source to a service brake device through a first brake valve having a non-operating region that does not operate until the depression amount; Serving pressure from a brake pressure source via a second brake valve that operates in conjunction with the brake pedal And an auxiliary brake circuit for outputting to the rake device, wherein a high-output side brake circuit is selected and connected to the service brake device, and an operation of the regenerative device is provided downstream of the second brake valve. And a determination means for determining whether or not an operation release condition is satisfied when the regenerative device is operated, and a vehicle speed. Vehicle speed detecting means for detecting, and when the determining means determines that the operation release condition is satisfied, the tilt angle of the pump motor is set to a predetermined value near a neutral position until the vehicle speed detected by the vehicle speed detecting means becomes zero. And a tilt angle control means for holding.

[0007]

In the above arrangement, when the brake pedal is operated, the output of the main brake circuit and the auxiliary brake circuit on the high pressure side is selectively supplied to the service brake device side. Therefore, in the non-operating region of the first brake valve, the pressure on the auxiliary brake circuit side is supplied to the service brake device side. At this time, if the operating condition of the regenerative device is satisfied, the output of the auxiliary brake circuit is stopped by the closing operation of the on-off valve, while the regenerative device is activated, and the pump motor is operated based on the amount of depression of the brake pedal at that time. The tilt angle of the oblique axis is set, and a regenerative braking force is generated according to the brake pedal depression amount.

During the regenerative braking, if the determining means determines that the condition for releasing the operation of the regenerative device is satisfied, the tilt angle control means controls the tilt angle of the pump motor until the vehicle speed becomes zero and the vehicle stops. Is set to a predetermined value near the neutral position. Thus, a slight load acts on the gear connecting the vehicle drive system and the pump motor from the pump motor side until the vehicle stops, so that gear rattling noise can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a piping diagram of an energy regenerative braking device for a vehicle according to the present invention. In FIG. 1, a brake pedal 1
The main brake valve 2 as a first brake valve interlocking with the depression operation of the brake pedal controls the air from the air reservoirs 14 and 15 in accordance with the depression amount such as the depression angle θb of the brake pedal 1 so that the primary circuit 18 and the secondary circuit Supply air to 19 respectively. The main brake valve 2 has a non-operation range depression angle θb of the brake pedal 1 does not output the air in the primary circuit 18 and secondary circuit 19 to reach a predetermined value theta _1. Here, the primary circuit 18 and the secondary circuit 19 constitute a main brake circuit.

Similarly, an auxiliary brake valve 3 as a second brake valve interlocked with the depression operation of the brake pedal 1 controls the air from the air reservoir 14 in accordance with the depression amount such as the depression angle θb of the brake pedal 1 to assist. It is supplied to the brake circuit 11. The auxiliary brake circuit 11 includes a limiting and quick release valve (hereinafter, LQ
And a normally open solenoid valve 7 as an on-off valve.
Is provided. The LQR valve 9 reduces the air pressure supplied to the auxiliary brake circuit 11 through the auxiliary brake valve 3 at a predetermined rate, and supplies the air pressure to the signal pressure ports of the relay valves 8 and 8 ′ through the electromagnetic valve 7. The solenoid valve 7 is
The regenerator 30 is driven by the controller 10 based on the detection value from the pressure sensor 6 that detects the air pressure Pb output to the auxiliary brake circuit 11 via the auxiliary brake valve 3.

The relay valves 8 and 8 'adjust the air from the air reservoirs 14 and 15 to an air pressure corresponding to the signal pressure from the LQR valve 9 and supply the air to one port of the double check valves 4 and 5, respectively. I do. The other ports of the double check valves 4 and 5 are connected to a primary circuit 18 and a secondary circuit 19. The double check valve 4 selects the high pressure side of the air pressure P3 on the relay valve 8 side and the air pressure P1 on the primary circuit 18 side and supplies the selected high pressure side to the rear wheel brake circuit 20. Air pressure P3 of valve 8 'and air pressure P of secondary circuit 19 side
2 is selected and supplied to the front wheel brake circuit 21.

A rear wheel brake circuit 20 connected to the double check valve 4 drives a brake chamber 24 via a relay valve 22, and a front wheel brake circuit 21 connected to the double check valve 5 via a quick release valve 23. To drive the brake chamber 25. These brake chambers 2
Reference numerals 4 and 25 are connected to a brake drum (not shown) to constitute a service brake device that applies braking to wheels.

As shown in FIG. 2, the regenerative device 30 is provided with a gear clutch 54a of a speed reducer 54 driven by the controller 10 on an output shaft of a transmission 52 that changes the speed of rotation of an engine 51 and transmits the speed to a rear wheel 53. The pump motor 31 of the oblique axis type is connected via the. One port of the pump motor 31 is connected to a high-pressure oil passage 34 connected to an accumulator 33 via a shut-off valve 32, and the other port is connected to a low-pressure oil passage 36 connected to a tank 35. Further, an oil filter 37 and an oil cooler 38 are interposed between the tank 35 and the shutoff valve 32, and an oil passage 39 for circulating the oil via the pump motor 31 during normal traveling is provided. I have.

The accumulator 33 is provided with a pressure accumulation level sensor 40 for detecting the amount of regenerated energy as the position of the piston 33a. The controller 10 includes a vehicle speed signal V from a vehicle speed sensor 41, a shift position signal from a shift lever 42, a pressure accumulation level signal L from a pressure accumulation level sensor 40 for detecting a pressure accumulation level L of an accumulator 33, and a pressure of the auxiliary brake circuit 11. A pressure signal Pb or the like from the pressure sensor 6 that detects Pb is input. Based on these input signals, the controller 10 determines that the pressure Pb of the pressure sensor 6, the vehicle speed V, the accumulated pressure level L, and the shift position satisfy predetermined conditions, as shown in a flowchart of FIG. If the operating condition is satisfied, the shut-off valve 32 of the high-pressure oil passage 34 is controlled to be opened, the solenoid valve 7 of the auxiliary brake circuit is controlled to be closed, the braking torque required by the driver is calculated, and the flow rate of the pump motor 31 is calculated. The tilt angle of the oblique axis is set according to the stepping angle and the accumulated pressure level so as to match the set value.

If any one of the vehicle speed V, the accumulated pressure level L, and the pressure Pb is out of the fulfillment condition during the operation of the regenerative device 30, the pump motor is driven until the vehicle speed V becomes V = 0. The tilt angle of the 31 oblique axis is set to a predetermined value AP near the neutral position.
It is set to o so that a slight load acts on the gear of the speed reducer 54 from the pump motor 31 side. Therefore, the controller 10 has functions of the tilt angle control means and the determination means.

Here, the depression angle θ of the brake pedal 1
The relationship between b and the air pressure generated by the main brake valve 2, the auxiliary brake valve 3, and the relay valves 8, 8 'will be described with reference to FIG. The area where the depression angle θb of the brake pedal 1 is less than θ ₁ is the area where the main brake valve 2
When the regenerative device 30 is at rest when the solenoid valve 7 is open, the air pressure Pb corresponding to the depression angle θb of the brake pedal 1 is transmitted from the auxiliary brake valve 3 through the auxiliary brake circuit 11. The LQR valve 9 has a characteristic in which the relationship between the input pressure and the output pressure is as shown in FIG. 4, and the air pressure reduced at a predetermined rate is sent to the relay valves 8, 8 'as a signal pressure. The air pressure P3 corresponding to the signal air pressure from the LQR valve 9 is output from the relay valves 8, 8 ', and the air pressure P3 is transmitted via the double check valves 4, 5 to the rear wheel brake circuit 20 and the front wheel. It is supplied to the brake circuit 21. When the air pressure P3 is equal to the brake pedal depression angle θb, the regeneration device 30
Since the pressure reduction characteristic of the LQR valve 9 is set so that a braking force equal to the braking force of
A braking force equal to the regenerative braking force by the regenerative device 30 is generated.

When the depression angle θb of the brake pedal 1 is θ ₁
When the brake pedal is depressed beyond the limit, the primary circuit 18 and the secondary circuit 19 are switched from the main brake valve 2 according to the depression angle.
While the supply of the air pressures P1 and P2 is started, the air pressure P3 on the auxiliary brake circuit 11 side maintains a constant pressure, and the air pressure P1 from the primary circuit 18 exceeds the air pressure P3 from the relay valve 8. depression angle θ until ₂ the air pressure P
A braking force is generated by the service brake according to (3).

When the step angle θb exceeds θ ₂ , the air pressures P 1, P ₂ on the primary circuit 18 and the secondary circuit 19 side
The service brake is actuated by the air pressure P
1 and P2. Next, the control operation of the controller 10 will be described with reference to the flowchart of FIG.

First, in step 1 (indicated by S1 in the figure, the same applies hereinafter), the pressure Pb of the auxiliary brake circuit 11 is read from the pressure sensor 6. In step 2, it is determined whether or not the read pressure Pb has exceeded a preset pressure Po, that is, whether or not the driver has depressed the brake pedal 1. Here, if the brake pedal 1 is depressed, Pb> Po is satisfied, and the routine proceeds to step 3, otherwise, the routine proceeds to step 11 and subsequent steps.

In step 3, the accumulator accumulation level L is read from the accumulation sensor 40. In step 4, it is determined whether the accumulated pressure level L exceeds a predetermined maximum accumulated pressure level Lmax, that is, whether the accumulator 33 is within the allowable accumulated pressure level. If L <Lmax, proceed to step 5,
Otherwise, go to step 14. In step 5, the shift position signal from the shift lever 42 is read, and
It is determined whether or not the vehicle is at a forward position where kinetic energy can be recovered. Here, if the gear position is the forward position, the process proceeds to Step 6, and if not, the process proceeds to Step 11 and the subsequent processes.

In step 6, the vehicle speed V from the vehicle speed sensor 41 is read, and it is determined whether or not the vehicle speed V is lower than a preset maximum vehicle speed Vmax which is the maximum allowable rotation speed of the pump motor 31. Proceed to step 7, and if NO, proceed to step 11. In step 7, it is determined whether or not the vehicle speed V is higher than a preset minimum vehicle speed Vmin.
In the case of ES, the kinetic energy is recovered by the operation of the regenerative brake, which will be described later, in step 8 and subsequent steps.

That is, when the pressure of the auxiliary brake circuit 11 exceeds Po, if the accumulated pressure level L is smaller than Lmax, the gear position is the forward position, and the vehicle speed is within a predetermined range, the operation of the regenerative device 30 is started. If it is determined that the condition is satisfied, the braking by the regenerative brake is performed by the processing of step 8 and the following. If at least one of the above conditions is not satisfied, the processing of step 11 and the following is executed to perform the braking by the service brake device. Do. When the operation release condition is satisfied in steps 4 and 7 during the regenerative braking, the process proceeds to step 14, where it is determined whether or not the vehicle speed V has become V = 0.
In the case of ES, the processing after step 11 is executed, and
In the case of, the routine proceeds to step 15, where the tilt angle A of the pump motor 31 is
P is set to a predetermined value APo near the neutral position.

When the operating condition of the regenerative brake is satisfied,
In step 8, the shut-off valve 32 is opened, and in step 9, the tilt angle AP of the oblique axis of the pump motor 31 is changed to the pressure accumulation level L such that a braking force corresponding to the depression angle θb of the brake pedal 1 at that time is generated. Variable setting according to
In step 10, the solenoid valve 7 of the auxiliary brake circuit 11 is driven to close. As a result, the supply of the signal pressure to the relay valves 8 and 8 'is interrupted to stop the supply of the air pressure to the service brake device side, while the driving force of the rear wheel 53 causes the pump motor 31 to operate as a pump. As shown by an arrow A in FIG. 2, the oil in the tank 35 is pressure-fed to the accumulator 33 and accumulated to recover kinetic energy and at the same time generate regenerative braking force.

During the regenerative braking operation, if the accumulated pressure level L satisfies L ≧ Lmax in step 4 or if the vehicle speed V satisfies V ≦ Vmin in step 7 and the operation release condition is satisfied, step 14 is executed. , 15, the vehicle speed V is V =
Until it becomes 0, the tilt angle AP of the pump motor 31 is set to a predetermined value APo. As a result, even if the mode is switched from the regenerative brake to the service brake, the gear in the speed reducer 54 connecting the pump motor 31 and the drive system of the wheels is slightly shifted from the pump motor 31 side until the vehicle speed becomes zero. A heavy load acts on the gear, preventing idling of the gear and reducing gear rattle.

When the vehicle speed V becomes V = 0 and the vehicle stops, the solenoid valve 7 is opened in step 11 and the tilt angle A
P is returned to the neutral position of AP = 0, and the shutoff valve 32 is driven to close so that the operation of the regenerative device is completely stopped. Also, when the brake pedal 1 is depressed, the operating condition of the regenerative device 30 is not satisfied, and when the service brake is operating, the solenoid valve 7 is opened and the tilt angle AP of the oblique axis of the pump motor 31 is set. The neutral position is set, and the shutoff valve 32 is driven to close. As a result, the regenerative device 30 does not operate, and the oil in the tank 35 is filled with the oil passage 39, the shut-off valve 32, the pump motor 31, as shown by the arrow B in FIG.
The oil circulates through the low-pressure oil passage 36, and is purified and cooled by the oil filter 37 and the oil cooler 38. At this time, the air pressure Pb supplied to the auxiliary brake circuit 11 via the auxiliary brake valve 3 is reduced at a predetermined rate by the LQR valve 9 and supplied to the relay valves 8, 8 'as a signal pressure, as described above. The air pressure P3 corresponding to this signal pressure is supplied from the relay valves 8, 8 'to the double check valves 4, 5.
In the non-operating region of the main brake valve 2, the output from the auxiliary brake circuit 11 is used to perform braking by the service brake by the rear wheel brake circuit 20 and the front wheel brake circuit 21. 18
The higher of the pressures P1, P2 on the secondary circuit 19 side and the pressure P3 on the auxiliary brake circuit 11 side is selected and supplied to the brake circuits 20, 21 for the rear and front wheels to operate the service brake.

In starting the vehicle, the shutoff valve 32 is opened, the tilt angle of the oblique axis of the pump motor 31 is set to the neutral position, and the pump motor 31 is connected to the output shaft side of the transmission. The high-pressure oil of the arrow C in FIG.
The kinetic energy which flows to the tank 35 side and is collected by the pump motor 31 acting as a motor is used as drive energy.

In this embodiment, the relationship between the depression angle of the brake pedal and the tilt angle is controlled by the inversely proportional relationship so that the tilt angle AP becomes smaller as the pressure accumulation level L increases. Is controlled to change. Therefore, when the depression angle of the brake pedal 1 is kept constant during the operation of the regenerative device 30, when the accumulated pressure level L rises with the passage of time, the tilt angle AP is controlled to gradually decrease in accordance with this, and the constant. Regenerative braking force can be obtained. And this regenerative braking force F
b and the service brake force by the pressure P3 from the auxiliary brake circuit 11 are equal to the same brake pedal depression angle θb
Are set to be equal.

Therefore, when the condition for releasing the operation of the regenerative brake is satisfied and the regenerative brake is switched to the service brake, the brake force is substantially equal without any step difference, so that the feeling of idling or shock is reduced. Can be prevented. In this embodiment, the main brake pedal 2
Since the auxiliary brake circuit 11 for generating the service brake pressure is provided in the non-operating region of the vehicle, even if the regenerative device 30 fails, the service brake can be operated by the pressure from the auxiliary brake circuit 11, so that the regenerative device There is also an effect that the fail-safe property at the time of failure of 30 is ensured and the reliability of the brake device is improved.

[0029]

As described above, according to the present invention, when the condition for releasing the operation of the regenerative brake is satisfied and the operation of the regenerative brake is stopped, the pump motor is not operated until the vehicle speed becomes zero. Since the tilt angle is set to a predetermined value near the neutral position, a small load acts on the gear connecting the pump motor and the vehicle drive system from the pump motor side until the vehicle stops. Gears are prevented from idling,
Gear rattle noise at the time of switching from the regenerative brake to the service brake can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a brake piping system of an energy regenerative braking device for a vehicle according to the present invention.

FIG. 2 is a configuration diagram showing one embodiment of a regenerative device.

FIG. 3 is a diagram showing a relationship between a brake pedal depression angle and pressures of a main brake circuit and an auxiliary brake circuit.

FIG. 4 is a diagram showing a relationship between an input and an output of the LQR valve of the present embodiment.

FIG. 5 is a flowchart illustrating a control operation of the controller according to the embodiment.

FIG. 6 is a diagram for explaining an operation state of the regenerative device when switching from the regenerative brake to the service brake according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake pedal 2 Main brake valve 3 Auxiliary brake valve 4, 5 Double check valve 6 Pressure sensor 10 Controller 11 Auxiliary brake circuit 18 Primary circuit 19 Secondary circuit 20 Rear wheel brake circuit 21 Front wheel brake circuit 30 Regenerative device 41 Vehicle speed sensor 54 Reduction gear

Continuation of the front page (72) Inventor Nagayoshi Nakazono 1-chome, 1-chome, Ageo-shi, Saitama Nissan Diesel Industry Co., Ltd. (56) References JP-A-7-266912 (JP, A) JP-A-7-266914 ( JP, A) JP-A-7-266915 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60T 1/10 B60K 25/00

Claims (1)

(57) [Claims] When a regenerative brake operation condition is satisfied at the time of operating a brake pedal, a tilt angle of an oblique axis of a pump motor is controlled in accordance with an amount of depression of the brake pedal and the wheel drive system is driven by a gear. An energy regenerative braking device for a vehicle comprising a regenerative device connected to and driven by a pump motor to accumulate high-pressure oil in an accumulator to collect brake energy and to obtain a regenerative braking force according to the amount of depression of the brake pedal. A main brake circuit for outputting a pressure from a brake pressure source to a service brake device through a first brake valve having a non-operating region in which the brake pedal does not operate until a predetermined depression amount of the brake pedal; Pressure from a brake pressure source via a second brake valve that operates in conjunction with the brake pedal even in the non-operating range of An auxiliary brake circuit that outputs force to the service brake device, and selects a high-output brake circuit to connect to the service brake device. The regeneration circuit is provided downstream of the second brake valve. In a configuration in which an opening / closing valve that is driven to close and stops the output of the auxiliary brake circuit when the device is operated is interposed, a determination unit that determines whether an operation release condition is satisfied when the regenerative device is activated. A vehicle speed detecting means for detecting a vehicle speed, and when the determining means determines that the operation release condition is satisfied, the tilt angle of the pump motor is set near the neutral position until the vehicle speed detected by the vehicle speed detecting means becomes zero. An energy regenerative braking device for a vehicle, comprising: a tilt angle control means for maintaining a predetermined value.